[julia-users] "Filled" regions in Gadfly

[Tom Nickson]

When regressing, I quite like to plot my variance as a filled region behind 
the mean - as in this example from the GPML website.
<http://www.gaussianprocess.org/gpml/code/matlab/doc/f2.gif>
assuming I had data:

x, mean, std_dev 

and I wanted to plot mean against x and (mean +/- std_dev) against x as a 
filled regions, how would I set up my dataframe and call plot?

Double points if everything comes up nicely on the plot legend!

Tom